In recording or reproducing PCM signals in general, coding errors are caused in known manner due to defects in the recording medium, troubles in recording or reproduction, noises or disturbances. Thus an encoder is provided at the recording side to effect interleaving (data rearrangement) or addition of parity or error correcting codes, while a decoder is also provided at the reproducing side to effect deinterleaving (the reverse of interleaving), error detection and correction, or data interpolation.
When plural recording tracks are associated with each channel of single-channel or multichannel PCM signals for recording or reproduction, the signals are first passed through the aforementioned encoder, and are then distributed by switching distributing means, such as a multiplexer, to the recording heads. In this case, even when the interleaving operation is performed at the encoder in accordance with a predetermined rule, the effect of interleaving may be lowered at the time that the signals are distributed to the respective tracks by the multiplexer. In addition, since the error correcting code words are provided to the respective word rows allotted to plural tracks, it becomes impossible to perform a normal error correction in the event that the signals are absent in a given track for a prolonged time. Moreover, the allowable limit for error occurrence becomes narrow as a whole.
In view of the foregoing, it is a principal object of the present invention to provide a method of recording PCM signals according to which, when the PCM signals for one channel are distributed and recorded in plural tracks, the encoding operation such as the aforementioned interleaving or addition of error code may be improved in validity, thus assuring high-quality recording and reproduction of the PCM signals.